1. Field
This application relates to squares and protractors used in the construction and other trades.
2. Prior Art
This application relates to instruments for use in squaring and more generally in setting angles, and particularly, to a square or protractor incorporating a light beam generator mounted to project a beam at an angle to the base and used at a distance from the angle being squared.
Squaring devices and protractors having lasers for alignment are known. Some squares provide two and three simultaneous laser output beams at 90° and are placed at the apex of the angle being squared or set. Other devices include a laser and operable dial, where the dial allows the user to adjust the angle of the projected beam. These instruments are used by placing them at the apex of the angle being adjusted.
Other squares or protractors incorporate beams at an angle to the base for setting known angles relative to the base or have adjustable beams for adjusting to angles other than 90°. Common angles in these devices are 30°, 45° and 60°.
A common feature of the known squaring devices is that they require the square to be positioned at the apex of the angle being adjusted or measured.
This application presents an instrument that can be used to set two members to a specific angle to each other while positioned at a distance from the apex of the angle being squared or set. This provides a great advantage over the existing instruments. When the square or protractor is positioned at the apex of the angle, it present the problem of how to keep the instrument in position and aligned when the user needs to be at the end of one of the members that is away from where the two members meet. Typically, this is where the user is positioned when adjusting the angle between the two members. If this adjustment must be made while on a ladder, this factors present even greater difficulties for the user. Since the instrument presented in this application works at a distance from the apex; it can be positioned where the user is while making adjustments. A further advantage is that that since it works over greater distances, errors caused by warpage or maladjustments are averaged over greater distances. This results in a more accurate measurement.